Rock and like drill



June 30, 1942.

J. ARTHUR ROCK AND LIKE' DRILL 3 Sheets-Sheet l Filed Nov. 17, 1939 June 30, 1942. J. ARTHUR ROCK AND LIKE DRILL Filed Nov. 17, 1959 3 Sheets-Sheet 2 IHVEHTOQ l ATTORNEY.

w a w June 30, 1942. J. ARTHUR ROCK AND LIKE DRILL -Fil ed Nov. -1'7, 193,9

3 Sheets-Sheet 3 INVENYOQ ,5; ATTORHEY.

Patented June 30, 1942 ROCK AND LIKE DRILL John Arthur, Camborne, England Application November 17, 1939, Serial No. 304,897 In Great Britain April 26, 1939 4 Claims.

This invention relates to rock and like drills, more particularly to high speed rotary drills employing diamond or abrasive bits, and has for its object to provide an improved construction and arrangement of the motor and driven unit in such drills.

According to the invention the drill rod is arranged concentrically of the motor by which it is driven. In normal drill practice this will involve that the drill rod spindle is arranged axially of the motor, the motor revolving around the axis of the driven unit.

In the preferred construction according to the invention a sleeve-like member, by which the drill is driven, is arranged within and concentrically of the motor by which it is driven.

Hitherto in such drills the arrangement has been such that the drill rod spindle is placed independent of the motor drive and arranged to be swung aside for the withdrawal of the drill rod from the hole being drilled. This necessitates the provision of special gearing between the drill rod spindle and the motor with consequent unnecessary weight. With the present construction and arrangement of the motor and driven unit, arrangements may be made for withdrawing the drill rod axially through the motor so that the aforesaid special gearing is rendered unnecessary, vibration is reduced to a minimum with consequent increased drilling efficiency, and the drill when replaced still remains in its setting as at the commencement of the hole.

One embodiment of the invention will now be more particularly described, by Way of example, with reference to the accompanying drawings, in which Figure l is an axial section through the air motor of a drifter diamond drill having the drill rod spindle arranged according to the invention, the drill rod being shown in its operative position, and

Figures 2 and 2a together are a similar view to Figure 1 showing the withdrawal of the drill rod through the motor.

In this embodiment of the invention an air motor is employed, the drill being operated from a source of compressed air; the invention is applicable however to drills provided with other types of motor. As shown, the motor is of the vane type and is housed within a casing 3 slidably arranged on motor guide rods 4. The rotor 5 having vanes 5a is provided with antifriction bearings between it and the motor casing 3; as

shown the front of the rotor runs in a ball bearing 9 while the back of the rotor is carried in a roller bearing 1. The drill rod spindle 8 and its driving sleeve 9 run centrally through the rotor 5, the latter being arranged around the driving sleeve, Figure 1. At its front end the rotor 5 is provided with internal splines SD or other suitable connecting means in mesh with external splines 9b on the spindle driving sleeve 9. The latter is provided with front and back antifriction bearings H], II, as shown of the taper roller pattern, between it and the motor casing 3 and at its rear end has internal splines 90 with which are engaged external splines on the rear end of the drill rod spindle 8. This end of the drill rod spindle also carries a fixing nut l2 which screws on to an external thread at the rear end of the spindle driving sleeve 9, the fixing nut l2 being secured on the end of the drill rod spindle 8 by means of a nut l3.

The lower part of the motor casing 3 carries a nut l4 through which passes a feed screw l5 by rotation of which the motor casing and consequ-ently the drill rod l6 may be advanced or retracted towards or away from the rock face being drilled. It will be apparent from the foregoing description that the drill rod is driven by the rotor 5 through the intermediary of the spindle driving sleeve 9, the rotation of the rotor driving the spindle driving sleeve through the splined coupling 52), 9b while the rotation of the spindle driving sleeve in turn drives the drill rod spindle 8 through the splined coupling 90, 8c.

Rotation of the drill rod spindle 8 produces rotation of the drill l6 which has a screw coupling 11 therewith.

The spindle driving sleeve 9 is of somewhat larger internal diameter than the front end 8a of the drill rod spindle into which the drill rod I 6 is screwed at ll and the drill rod spindle 8 and drill rod I 6 may be completely withdrawn from the motor rearwardly through the spindle driving sleeve 9 merely by undoing the spindle fixing nut I 2. This manner of withdrawal is illustrated in Figures 2 and 2a which show the spindle fixing nut 12 removed from the screw thread 9a on the end of the spindle driving sleeve and the drill rod spindle 8 drawn rearwardly through the spindle driving sleeve taking with it the drill rod l6 which is shown in the process of passing rearwards through the motor.

A water chamber I8 is provided at the rear end of the motor casing 3 between the latter and the rear end of the spindle driving sleeve, the

chamber being closed by suitable packing washers l9 between the casing and the sleeve. Similar packing washers 28 are disposed one at each end of the rotor 5 to prevent access of water or grit thereto. The spindle driving sleeve 9 is drilled at 9d to permit passage of the water through diametrical holes 8d of the drill rod spindle into the central bore 81) of the latter. From the bore 81) of the drill rod spindle the Water passes into the hollow drill rod It, the latter being of the so-called diamond core type in which water passes through the bore lfia to the drill bit. The arrangement of water chamber described does not necessitate any extension to the overall length of the machine, as is the case with the usual water chamber constructions, thereby resulting in a short machine the advantages of which are known to those skilled in mining practice.

What I claim and desire to secure by Letters Patent is:

1. A rock or like drill embodying therein a motor having a hollow rotor, a hollow sleeve within and connected with said rotor, a drill shaft extending axially through said sleeve, a drill rod carried by one end of said shaft, connections between said sleeve and said shaft for imparting rotary movement by said sleeve to said shaft, and permitting axial movement of said shaft in relation to said sleeve, a member mounted upon said shaft adjacent the end thereof and engaging said shaft to prevent an axial thrust of said shaft rearwardly of the drill, and co-operating means upon said sleeve and said member whereby said member may be detachably connected with the rear end of said sleeve and, by disengagement of said member from said sleeve, said shaft may be withdrawn axially from said sleeve and the connections between said shaft and said sleeve may be made inoperative.

2. A rock or like drill emboding therein a motor having a hollow rotor, a hollow sleeve within and connected with said rotor, a drill shaft extending axially through said sleeve, a drill rod carried by one end of said shaft, connections between said sleeve and said shaft for imparting rotary movement by said sleeve to said shaft and permitting axial movement of said shaft in relation to said sleeve, a nut mounted upon and engaging the end of said shaft, and co-operating screw threads upon said nut and upon said sleeve whereby said shaft is secured against longitudinal movement within said sleeve and with the removal of said nut, said shaft and the drill rod may be moved axially of said sleeve to disengage the connections between said sleeve and said shaft and remove said shaft from its operative relation to said sleeve.

3. A rock or like drill embodying therein a motor having a hollow rotor, a hollow sleeve within and connected with said rotor, a drill shaft having a longitudinal opening extending axially through said sleeve, a hollow drill rod connected with said shaft, and means upon said shaft forming a water chamber adjacent one end thereof, said shaft having ports therethrough communicating with the longitudinal opening in said shaft, connections between said sleeve and said shaft for imparting rotary movement by said sleeve to said shaft, and permitting axial movement of said shaft in relation to said sleeve, a member mounted upon said shaft adjacent the end thereof and engaging said shaft to prevent an axial thrust of said shaft rearwardly of the drill, and co-operating means upon said sleeve and said member whereby said member may be detachably connected with the rear end of said sleeve and, by disengagement of said member from said sleeve, said shaft may be withdrawn axially from said sleeve and the connections between said shaft and said sleeve may be made inoperative.

4. A rock or like drill embodying therein a motor having a hollow 'rotor, a hollow sleeve within and connected with said rotor, a drill shaft having a longitudinal opening extending axially through said sleeve, a hollow drill rod connected with said shaft, and means upon said shaft forming a water chamber adjacent one end thereof, said shaft having ports therethrough communicating with the longitudinal opening in said shaft, connections between said sleeve and said shaft for imparting rotary movement by said sleeve to said shaft and permitting axial movement of said shaft in relation to said sleeve, a nut mounted upon and engaging the end of said shaft, and co-operating screw threads upon said nut and upon said sleeve whereby said shaft is secured against longitudinal movement within said sleeve and with the removal of said nut, said shaft and the drill rod may be moved axially of said sleeve to disengage the connections between said sleeve and said shaft and remove said shaft from its operative relation to said sleeve.

JOHN ARTHUR. 

